RTV Molding & Casting
Urethane & Silicone Casting
When multiple parts are needed, RTV (room temperature vulcanized) tooling and urethane casting can be used to fill the gap between prototype and production. Urethane prototypes can be of nearly any size and shape and can be color matched by either a pantone number or a color chip. Whether you require inserts, over molding, copper shielding, molded in color/texture or painted in custom color/texture with applied graphics, our urethane casting department will meet your required specifications.
Parts may be cast in a wide range of materials/durometers including shore 00 (gel-like), shore A (silicone & rubber), and shore D (plastic). Most materials can be custom color matched to a customer provided sample or pantone number; parts cast from shore-D materials can be painted any color
The Casting Process
The master pattern is created via 3D printing from the 3D part file. The 3D printed master then is finished, textured, and dimensionally verified to ensure customer satisfaction.
Once the master pattern is complete we then use it to create the silicone mold. The molds are generally good for up to 25 parts before needing to be replaced.
Urethane or silicone is then cast (injected) into the mold to create the cast parts. These parts are similar to injection molded parts, many customers use cast urethane parts as production pieces.
Generally a silicone mold will max out at 25 parts, softer durometer parts such as those on the “shore A” scale will allow for some extra parts; optically clear parts will generally only allow for a maximum of 20 parts from a single silicone mold.
We’ve cast parts in excess of 8 feet long, 4 feet wide, and over 500 cubic inches in volume.
Yes, many times a customer only requires annual volumes of 100 parts or less. When quantities are that low cast urethane or silicone parts is a great way to fill the order, and will save substantial money when compared to traditional injection molding.
Yes, however there are some things to keep in mind. Most of the casting materials have a shrink rate, and when we build the master patterns here at Schmit we compensate for the shrink rate for the material that will be used to create the cast parts.